Safety-switch.



A. K. SUTHERLAND.

SAFETY SWITCH.

APPLICATION FILED MAY 4. 1916.

Patented Apr. 24, 1917.

2 SHEETS-SHEEL l xY/eza del' [Julia/land A. K. SUTHERLAND.

SAFETY SWITCH.

APPLICATION FILED MAY 4. I916.

Patented Apr. 24,1917.

2 SHEETS-SHEET 2.

fl/ezamie/ufJaMer/and UNITED STATES PAENT OFFICE.

ALEXANDER K. SUTHERLAND, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THETRUMIBULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVILLE, CONNECTICUT,

A CORPORATION OF CONNECTICUT.

' sAnn'rY-swrrcn.

Specification of Letters Patent.

Patented Apr. 24; 191?.

Application filed May 4, 1916. Serial Ito. 95,299.

To all whom it may concern:

Be it known that I, ALEXANDER K. SUTH- ERLAND, a citizen of the Dominionof Canada, and subject of .King George V, residing at New Britain,Connecticut, have inty e The main object is to provide a construction inwhich the contacts and fuses or other protective devices are normallyinclosed and which cannot be exposed except in the open circuit or ofiposition. Another object is to provide a construction of this characterwhich can be locked in the open circuit position so as to prevent theoperation of the switch by unauthorized ersons. Another object is toprevent the closing of the circuit when thecontact parts are exposed.Another object is to provide a construction of the. above characterhaving a quick break or circuit opening action.

Figure 1, is a front view of the construction embodying the improvements.of my invention, the cover of the inclosure being shown open. Thisshows a switch for carrying two lines or both branches of a single line.One fuse is omitted from this figure.

Fig. 2, is a vertical sectional view on the plane of the line 22 of Fig.1 but showing the cover closed. The switch is shown in full lines in theopen circuit position and the operating handle is also shown dotted inthe position which it would occupy if locked against movement or if thecircuit had been thrown on or closed.

Fig. 3, is a sectional view on a larger.

scale on theplane of the line 33 of Fig. 1 showing the contact operatingmechanism.

Fig. 4, is a view similar to Fig. 2 but on a larger scale and showingthe switch elements in the closed circuit or on position. This alsoshows in dotted lines a part of the operating member and a part of thecover in the partially open position.

Fig. 5, is a side view showing a modified form of mechanism forcontrolling the movement of the switch, the parts being in the opencircuit position.

Fig. 6, is a similar view, the parts being in the closed circuitposition.

Fig. 7 is a sectional view on the plane of the line 7 of Fig. 5.

Fig. 8, is-a fragmentary view of part of the cover and operating memberwith an indicator.

The main stationary contacts 10, 10 are preferably inclined toward eachother and supported by a suitable insulating base 11. The movable switchmember is preferably made in two parts 12, 12 each of which is laminatedand carried by an insulating member 13. The switch member 12 is securedto the carrier 13 by a screw 14 which passes through the carrier 13 andthe switch member 12 and is screwed into the plate 15.

which is thus interposed between the upper and lower switch members 12,12. The adacent ends of the switch members 12 may be separated by aninsulating barrier 18. The carrier 13 is supported by brackets 20, 20 towhich it is secured by screws 20. The brackets are guided by standards21, 21, each of which has a slot 21 to receive the studs 22 and 23 whichare secured to the bracket 20. The spring 24: pulls outward on thebrackets so that in the open circuit position the studs .22 are in theouter ends 'of the slots 21. members 12, 12 may be moved to" the closedcircuit or on position by means of two arms 25 and 26 hinged together at27.. and having one end of one hinged at 28 to one standard 21 and theopposite end of the other hinged to the stud 23 of one of the carrierbrackets. The tension of the spring 24 when the parts are in the closedcircuit position holds the toggle arms pressed against the stop 29.

A stop 30 is mounted on each of the studs 23 and held,v by a spring 31in the position shown in Fig. 2 where one arm of the stop engages thepin32 on the arm 26. This .This plate 15 carries a clip 16 for a fuse 17The carrier 13 and the switch stop makes it impossible to close theswitch I the shoulder 35 has been engaged. It is thuspossible when theparts are m the position engages the shoulder 37.

circuit through the switch,

shown in full lines in Fig. 2 to close the switch by simply pulling downon the handle 33 at which time the inner end of the arm 33 engages theshoulder 35 and tilts the stop 30 and then engages the shoulder 36 tomove the toggle arms into the position shown in full lines in Fig. 4. Toopen the the handle 33 is moved upward from the position shown in Fig. 4so that the inner end of the arm 33 As soon as the toggle arms have beenmoved so that the connection 27 passes the line of centers between 23and 28, the spring 24 will throw the switch open with a snap action outof the control of the operator.

The inclosure consists of the box body 40 and the cover 41 hinged at 42.Preferably a. spring catch 43 is secured to the body adapted to projectthrough the slot 44 in the cover as shown in Fig. 2. The end of thiscatch may be perforated to accommodate the hasp of a padlock 45 forlocking the cover in the closed position. The rod 34 is secured in thecover of the box and is engaged by hooks 46 on the arms 25 when theparts are in the position shown in Fig. 4. It is thus impossible to openthe cover of the box when the switch is in the closed position as shownin Fig. 4. hen the switch is in the open circuit position as shown inFig. 2, the hooks 46 are retracted from the rod 34 so that the cover maybe opened upon removing the pad-lock 45 and releasing the catch 43. Whenthe cover is closed with the handle in the full line position of Fig. 2,the inner endsof the arms 33 pass between the shoulders 36 and 37 intoposition to engage the stop shoulders 35 and 36 for releasing the stopsand closing the switch.

If the cover of the box is closed with the operating handle in thedotted position of Fig. 2 it will be noted that the inner end of thearm33 does. not pass between the shoulders 36 and 37 but comes above theshoulder 36 and it is thus impossible to move the operating handle andarms so as to operate the switch.

It is of course possible to close the switch manually when the cover isopen by retracting the stops 30 with the fingers. If this is done forany .reason and it is then attempted to close the cover the inner end ofthe operating arms, ifin the dotted position of Fig. 4, will engage-theshoulder 36 and trip the toggle so as to automatically open the switch.If the arms 33 are not moved high enough to engage the stops 36 it isnot possible to close the cover with the switch in the closed circuitposition since the rodf34 will engage the' hooks 46 substantially inline with the toggle axes.

The contact parts of the switch may be covered by an insulating plate orplates such as 50 so as to prevent accidental engagement therewith whenthe cover of the box is open. This plate 50 may be secured to lugs 51 onthe side ofthe box by means of thumb nuts and studs52.

The slots 53 through which the handle arms 33 extend may be covered bystrips 54 held in place by projections 55. The condition of the circuitmay be indicated by words on and off on the outer side of the cover,which words are adapted to be covered by a shield 56 movable with one ofthe strips 54 and the corresponding handle arm so that when for instancethe word off is disclosed, as shown in Fig. 8, the circuit will be openand when the word on is disclosed the switch will be closed.

Instead of the toggle arm construction for holding the switch in theclosed circuit position I may employ a cam plate 60 such as shown inFig. 5 which cannot be closed by ordinary pressure because the stud 23'will engage in the notch 61. The cam plate is provided with a shoulder62 adapted to be engaged by the operating arm 33 (previously described)to move the switch to the closed circuit position. In this movement thecam 63 forces the roller 64 on the stud 23 to the position shown in Fig.6 and the tension of the spring 24 holds the roller in the recess 65with the switch in the closed circuit position. vided with a shoulder 66adapted to beengaged by the inner end of the operating arm 33(previously described) to open the switch.

What I claim is:-

- 1. In a switch construction, stationary and movable contacts, aninclosure therefor including a movable cover, a hinge member connectedto said movable contact and having two shoulders spaced apart from eachother and an operating handle pivotally carried by the cover and havingan arm adapted to swing between said shoulders when the cover is closedwhereby the circuit may be controlled.

2. In a switch construction, stationary and movable contacts, aninclosure therefor including a movable cover, a hinge member connectedto said movable contact and having two shoulders spaced apart from eachother, an operating handle pivotally carried by the cover and having anarm adapted to swing between said shoulders .when the coveris closedwhereby the circuit may be controlled and interlocking parts carried bysaid hinge member and by said cover for preventing the cover from beinopened when the contacts are in closed circult position.

3. In a switch construction, stationary The cam plate is also proother,an operating handle pivotally carried by the cover and having an armadapted to swing between said shoulders when the cover is closed wherebythe circuit may be controlled and a stop for normally preventing theclosing of the circuit, said stop being adapted to be released by saidoperating arm.

4. In a switch construction, stationary contacts, slotted standards, aninsulating carrier, studs projecting from the ends thereof into saidslotted standards, members hinged to said standards and having meansofconnection with one of the studs in each slot, a stop movable with oneof said hinge members and an operating handle for moving said hingemembers to close and open the circuit.

5. In a switch construction, a stationary contact, a stationary slottedstandard, a carrier having means projecting into the slot of saidstandard, a contact carried by said carrier, an arm hinged to saidstandard, a second arm hinged to said first mentioned arm and alsohinged to said carrier, one of said arms having two laterally projectingshoulders and a hinged operating member adapted to oscillate betweensaid shoulders, a spring normally tending to pull said carrier so as toseparate the contacts and a stop for one of said arms to limit itsswinging movement and permit the spring to hold the parts in the closedcircuit position.

6. In aswitch construction, a stationary contact, a stationary slottedstandard, a carrier having means projecting into the slot of saidstandard, a contact carried by said carrier, an arm hinged to saidstandard, a second arm hinged to said first mentioned arm and alsohinged to said carrier, one of Silldo arms having two laterallyprojecting shoulders'and a hinged operating member adapted to oscillatebetween said shoulders, a spring normally tending to pull said carrierso as to separate the contacts, a stop for one of said arms to limit itsswinging movement and permit the spring to hold the parts in theclosedcircuit position and a stop movable with said carrier adapted tobe automatically closed by said operating member.

. 7. In a switch construction, a stationary contact, a stationaryslotted standard,.a carrier having means projecting into the slot ofsaid standard, a contact carried by said carrier, an arm hinged to saidstandard, a second arm hinged to said first mentioned arm and alsohinged to said carrier, one of said arms having two laterally projectingshoulders and a hinged operating member adapted to oscillate betweensaid shoulders, a spring normally tending to pull said carrier so as toseparate the contacts, a stop for one of said arms to limit its swingingmovement and permit the spring to'hold the parts in the closed circuitposition and a stop movable with one of said arms and adapted to beretracted by said operating member.

8. In a switch of the character described, a box and a movable covertherefor, switch contacts supported wholly in the box, switch operatingmeans mounted in the box and an operating handle supported on the coverand movable therewith, said operating handle having an operativeconnection with the switch operating mechanism freely disengageabletherefrom when the cover is opened,

9. In a switch construction, a box and a movable covertherefor, switchcontacts mounted wholly in the box, switch operating means mounted inthe box, an operating handle mounted on the cover and movable therewithand operating connections ,between said handle and switch operatingmeans disengageable when the cover is open and operatively engageable asthe cover is closed only when both the switch operating means and theoperating handle are in the open circuit positions.

10. In a switch construction, a box and a movable cover therefor,relatively stationary and movable switch contacts mounted wholly in thebox, pivoted levers supported in the box and connected with the movableswitch contact for operating the same, an operating handle mounted onthe cover and movable therewith and operating connections between saidhandle and the switch operating levers disengageable as the cover isopened and engageable as the cover is closed.

ALEXANDER K. SUTHERLAND.

